Tiếng Việt
Onlays for patients with severe wear
Occlusal onlays made of lithium disilicate often present an effective treatment option in patients with severe wear. A small study from 2019 found a 100% success rate over 11 years in this context[2]. A more recent study supports these findings, showing a survival rate of 98.4% in patients with severe wear, with a 100% survival rate for inlays and a 85.7% survival rate for onlays[3]. These results suggests that IPS e.max lithium disilicate is suitable not only for anterior but also for posterior teeth. Although onlays may entail a higher risk of fracture in those cases, a survival rate of 85.7% after twelve years is clinically acceptable, as most of the tooth structure is preserved. Additionally, recent publications indicate that onlays generally require fewer post-prosthetic endodontic interventions compared to posterior crowns. If an onlay does fracture beyond repair, a crown can still be placed afterwards.
Long-term planning
Why should we rush the process? Why are we in such a hurry? Our goal should be to delay more invasive treatment, if possible. An onlay restoration can easily last for 10 or 20 years. If the onlay is no longer adequate after 20 years, it was still a worthwhile alternative up to that point. The patients have been well served, and other treatment options are still available. We should not jump to definitive, final treatments right from the beginning. Instead, why not provide patients with a solution that can last for 20 years and then another one for another 20 years?
IPS e.max Press lithium disilicate glass-ceramic
Our IPS e.max lithium disilicate glass-ceramic combines high strength and durability[4,5] with translucency and excellent esthetic properties. It is available both as conventional press ceramic, known as IPS e.max Press, and as CAD/CAM blocks, known as IPS e.max CAD. IPS e.max provides a hight stability of 470 MPa (IPS e.max Press) and 520 MPa (IPS e.max CAD) respectively[6,7], while long-term studies confirm its outstanding material properties. The fact that lithium disilicate glass-ceramic can be etched ensures that a strong micromechanical bond to the tooth structure will form during adhesive cementation. In addition, the material exhibits an enamel-like wear rate, contributing to lasting occlusal schemes. Alongside the survival rate, research from Dr Malament’s team shows that occlusal adjustments to ceramic restorations, followed by polishing of the adjusted area, do not impact the clinical longevity and durability of the restorations[4].
Conclusion
Partial restorations are a practical and often preferable alternative to crowns, and in many cases, they are the better choice. They are less invasive, preserve natural tooth structure, and can maintain the function and esthetics of teeth for many years, as demonstrated, for instance, in long-term studies conducted by Dr Malament and his team (published in the Journal of Prosthetic Dentistry, JPS, USA). By using clinically proven materials such as the IPS e.max Press lithium disilicate glass-ceramic and state-of-the-art techniques, you can offer your patients a conservative and lasting treatment that ensures long-term dental health and improves their quality of life in the long term.
